Based on extensive animal testing and limited human studies, transcutaneous immunization appears to be a viable and valuable technological improvement to traditional administration of vaccines. The aim of the proposed research plan is to continue commercialization of the technology through further clinical development of the lead tetanus booster product, administered by means of a simple skin patch. The critical activities in this program include: A Phase I human clinical study to further demonstrate safety and immunogenicity at lower adjuvant/antigen ratios. Product development in the area of formulation, analytical methodology, and patch design to yield a stable, commercially viable product design. A subsequent Phase I human study to evaluate the safety and efficacy of the proposed formulation(s) and patch design(s), at the appropriate dose of adjuvant and antigen. Specific outcomes of the work will be a product design that can advance to Phase II/III human studies required for regulatory licensure. Commercial opportunities for a tetanus booster product have been researched and identified, consisting primarily of developing world programs aimed at eliminating maternal and neonatal tetanus, and at-risk populations in developed countries, including those over 50 years of age and other specific at-risk groups. PROPOSED COMMERCIAL APPLICATION: The Transcutaneous tetanus booster is directed to 2 markets: 1. Maternal and neonatal tetanus elimination, primarily in developing countries; and, 2. Adult booster & at-risk population, including the over-50 population and other specific at-risk groups, such as agricultural workers. The commercial introduction of a tetanus vaccine delivered through a patch is expected to increase access to the vaccine and compliance with immunization protocols for the 2 focus markets, thus growing both markets. Additionally, the Transcutaneous booster will decrease the risk of needle-sticks and related disease, and reduce personnel and equipment requirements related to tetanus immunization.